When the transient response of a linear network to an applied unit step function consists of a monotonic rise to a final constant value, it is found possible to define delay time and rise time in such a way that these quantities can be computed very simply from the Laplace system function of the network. The usefulness of the new definitions is illustrated by applications to low pass, multi-stage wideband amplifiers for which a number of general theorems are proved. In addition, an investigation of a certain class of two-terminal interstage networks is made in an endeavor to find the network giving the highest possible gain—rise time quotient consistent with a monotonic transient response to a step function.

A system in which electrons are projected radially inwards from a spherical surface, has been proposed for the confinement of a plasma at thermonuclear temperatures. The equilibrium, economics, and stability of such a system are discussed theoretically. Although we conclude that it is of doubtful utility as a thermonuclear reactor, it may be possible to produce in this way small regions of thermonuclear plasma for study. The device appears to be unstable at economic densities. The stability is discussed in terms of a virial, which turns out to be mathematically tractable in this geometry.

An investigation of the electrolytic polishing of copper by the Jacquet method has thrown new light on the mechanism responsible for the polishing action. From a study of the voltage-current curves it is concluded that when conditions are right for polishing the concentration of dissolved copper at the anode is the highest possible. Accordingly the concentration gradient which exists at the anode limits the rate at which copper can dissolve,i.e., diffuse into the bulk of the electrolyte (orthophosphoric acid). Since there is greater diffusion from raised areas of the anode because of steeper concentration gradients near them, the surface will become progressively more nearly level. The surface does not etch for the concentration gradient alone controls the rate of solution. Details are given for the electrolytic polishing of iron with an orthophosphoric acid electrolyte. A convenient form of cell for electrolytic polishing is described.

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